17 research outputs found
Early-Season Phenology and Temporal Dynamics of the Common Asparagus Beetle, \u3ci\u3eCrioceris Asparagi\u3c/i\u3e (Coleoptera: Chrysomelidae), in Southern Minnesota
During the years 1991-1994, studies were conducted to determine the early-season phenology and temporal dynamics of Crioceris asparagi (L.) (Co- leoptera: Chrysomelidae) in southern Minnesota asparagus. To document the early-season phenology, asparagus plots were sampled for egg, larval, and adult stages of C. asparagi during the months of May and June. Temporal dynamics of C. asparagi were determined by measuring the diurnal activity of adults and sampling asparagus plots at specific times (7 am, 9 am, 11 am, 1 pm, 3 pm and 5 pm) throughout May and June. We first detected C. asparagi adults in early May and they remained active throughout the sampling period. Eggs and larvae were also found; larval infestations on spears, however, were consistently lower than those for eggs. The temporal dynamics of C. asparagi adults showed that a higher percentage of asparagus plants were observed to be infested with beetles during the afternoon hours of 1 and 5 pm. The information provided in this paper illustrates the importance of determining the optimum time of day for sampling and will assist in properly targeting sampling efforts in future asparagus research and integrated pest management (IPM) programs
Day-neutral Strawberry Production in Minnesota
Day-neutral strawberries differ from traditional June-bearing types in that they flower and fruit continuously when temperatures are moderate because they are insensitive to day length. This bulletin provides an overview of day-neutral strawberry establishment and management. Includes cultivar selection, spacing and planting, nutrient management, weed management, insect and disease management, and overwintering
Development of an Insect Herbivore and its Pupal Parasitoid Reflect Differences in Direct Plant Defense
Grape Insect Pests of the Home Garden, M1236
PDF version of web content. Extension Bulletin no. M1236. This archival publication may not reflect current scientific knowledge or recommendations. Current information available from the University of Minnesota Extension: https://www.extension.umn.edu.Growing grapes is becoming increasingly popular for the home gardener. Once grapevines are established, they can be productive for over 40 years. The productivity of the grapevines relies heavily on the careful choices of the home gardener. Home fruit gardeners can be successful if they select the right cultivars, properly prune grapevines annually, and maintain good fertility and pest management programs.
Accurate insect identification is essential in any pest management program. In this publication we have compiled a list of insects commonly found on grapes in Minnesota. Please remember that careful, timely inspection of grapes and good cultural practices will aid in reducing the need for insecticide applications
Minnesota high tunnel production manual for commercial growers, 2nd Edition
This archival publication may not reflect current scientific knowledge or recommendations. Current information available from the University of Minnesota Extension: https://www.extension.umn.edu.Risk management, structures, the high tunnel environment, cultural practices, crop production, crops, and finances for growing in high tunnels in MinnesotaFunding for this revision was provided through partnership agreements with the Minnesota Department of Agriculture (MDA), the Minnesota Fruit and Vegetable Growers Association (MFVGA) and the United States Department of Agriculture – Risk Management Agency (RMA)
Sex determination meltdown upon biological control introduction of the parasitoid Cotesia rubecula?
Natural enemies may go through genetic bottlenecks during the process of biological control introductions. Such bottlenecks are expected to be particularly detrimental in parasitoid Hymenoptera that exhibit complementary sex determination (CSD). CSD is associated with a severe form of inbreeding depression because homozygosity at one or multiple sex loci leads to the production of diploid males that are typically unviable or sterile. We observed that diploid males occur at a relatively high rate (8–13% of diploid adults) in a field population of Cotesia rubecula in Minnesota, USA, where this parasitoid was introduced for biological control of the cabbage white Pieris rapae. However, our laboratory crosses suggest two-locus CSD in a native Dutch population of C. rubecula and moderately high diploid males survival (approximately 70%), a scenario expected to produce low proportions of diploid males. We also show that courtship behavior of diploid males is similar to that of haploid males, but females mated to diploid males produce only very few daughters that are triploid. We use our laboratory data to estimate sex allele diversity in the field population of C. rubecula and discuss the possibility of a sex determination meltdown from two-locus CSD to effective single-locus CSD during or after introduction.